Circuit interrupter



Patented Aug. 24, 1954 UNITED STATES PATENT OFFICE 2,687,462 y CIRCUIT INTERRUPTER Albert R. Cellerini, Beaver, Pa., assignor to Westporation, East Pittsburgh,

Pennsylvania Application February 16, 1950, Serial No. 144,461

inghouse Electric Cor Pa., a corporation of attained heretofore.

Another object is to provide an improved magnetic structure for a circuit interrupter of the air-break type employing a plurality of spaced metallic plates.

Another object is to provide an improved plate material for an interrupter of the spaced metallic plate type.

Further objects and advantages will readily become apparent upon reading the following specification taken in conjunction with the drawings, in which Figure 1 is a side elevational view, partially in vertical open circuit position;

Fig. 2 is a plan view of the magnetic circuit employed in my improved interrupter;

"Fig, 3 is a plan view of the arc chute subassembly.`

Fig. 4 is a side elevational view of structure shown in Fig. 2;

Fig. 5 is a side elevational view of subassembly shown in Fig. 3;

Fig. 6 is a vertical sectional view through the arc chute, the contacts being shown in the partially open circuit position;

Fig. 7 is a plan View of the pole face;

Fig. 8 is a plan view of a fiber deilector;

Fig. 9 is a plan View of one of the metallic plates of my improved arc chute;

Fig. 10 is a front elevational view of the liber support;

Fig. l1 is a plan view of an arc plate horn;

Fig. 12 is a side elevational view of the arc plate horn of Fig. 11;

Figs. 13 andl4 are plan and end views of the clamp for the arc plate horn, with Figs. l5 and 16 showing plan and side views of the completed arc plate horn subassembly; k

17 is a plan view of a ber deflector, and

the magnetic the arc chute Fig. 18 is a view of the piece of insulation which is Wrapped about each of the legs of the iron yoke before the blowout coils are placed thereabout.

Referring to the drawings, and more particubase 2 and a molded A handle or operating arm 4 projects through an opening 5 provided a three-phase circuit, for purposes of clarity only a single pole is shown. Obviously the other two poles of a multiphase breaker could be constructed similarly and, as is customarily done, are operated by the same mechanism 6.

A line terminal I0 is provided to carry current through a conductor II which is usually associated with a temperature responsive overload device, not shown, which will serve to trip the breaker I upon occurrence of excessive current passing therethrough. Since my invention is not actuating mechanism otherwise secured, to the moving contact arm l.

and through a pair of electrically-parallel blowout coils I5, I6 to a conducting strap, or terminal projecting portion Il, to which the line terminal I8 is attached.

My invention is particularly concerned with the are chute, generally designated by the reference numeral I9 in Figs. 3 and 5, and with the magnetic structure or frame 20 of Figs. 2 and 4.

The magnetic structure 20 includes a U-shaped member of soft iron 2I around the legs 22, 23 of which are wrapped a piece of insulation 24 (Fig. 18) which is preferably composed of any suitable insulating material, such as fish paper.

After theY sh paper strips 24 have been wound about the legs 22, 23 of the soft iron yoke 2|, blowout windings 25, 26, initially preformed, are slipped over the insulating strips 24 in the manner shown in Figs. 2 and 4. The left-hand ends 21 of the blowout coils 25, 26, as viewed in Fig. 2, are welded to the contact support plate I4. The right-hand ends 28 of the blowout coils 25, 26, as viewed in Fig. 2, are welded to the conducting strap I1. It will, therefore, be evident that the current passing through the interruptor i divides at the contact support plate I4 and passes through both blowout coils 25, 26 to the conducting strap I'I, and thence to the right-hand line terminal I8 of the interrupter I.

After the blowout coils 25, 26 have been placed on the legs 22, 23 of the soft iron yoke 2l over the fish paper strips 24, pole faces 29 (Fig. '1) are spot-welded to the extreme lefthand ends of the legs 22, 23 in a manner more fully shown in Fig. 2. Consequently, the energization of the electrically-parallel blowout coils 25, 26 serves to create an intense magnetic field between the pole faces 29, as indicated by the dotted lines 35 of Fig. 2. This magnetic field 39 serves to force the arc 3I, which is established between the stationary and movable contacts I3, 8 during the opening operation, toward the right, as viewed in Fig. 6, and into the arc chute I9, more fully described hereinafter.

The arc chute I9 will now be described. The arc chute I9 comprises an arc plate support 33 formed of a suitable gas-evolving insulating plate material, such as fiber, and a plurality of spaced non-magnetic conducting plates 34. The plates 34 are shown more clearly in Fig. 9, and it will be observed that they are provided with integrally formed lugs 35 and a slot 36, the latter extending inwardly from the left-hand side of the plate 34, as viewed in Fig. 9. The lugs 35 of the conducting plates 34 project through apertures 31 stamped in the fiber sheath 33, with the plates 34 staggered in such manner that the righthand lug 35 is disposed alternately along the front side 38 of the arc plate support 33.

At the lower end of the arc chute I9 is provided an arc plate runner or horn 39, shown more clearly in Figs. and 16, and comprising a conducting plate 40 having its front edge 4I turned up slightly, as shown in Fig.'l2. A U- shaped clamp 42 having projecting side lugs 43 ts under the plate 49 and is spot-welded thereto. Following the welding operation an aperture 44 is drilled through the subassembly 39 and is tapped. The tapped aperture 44 accommodates the upper end of a bolt, or screw, 45 which secures both the Contact support plate I4 and the arc chute I9 in position. It will be observed that the projections or lugs 43 of the clamp 42 extend through the lower apertures 31 of the arc plate support 33 so that by securing the arcing plate 40 rigidly in position to the base 2 by the bolt 45, correspondingly the arc chute I9 is likewise fixedly secured into its proper position.

The assembled arc chute I9 is placed within the interior of the magnetic structure 20, in a manner more clearly shown in Fig. 1 of the drawings. At the upper end of the arc plate support 33 is placed the deflector 46 (Fig. 8) which has lugs 41 which fit into notches 48 formed with the arc plate support 33. Also a deflector 49 (Fig. 17) is placed below the arc chute I9, as shown in Fig, l, to deflect the arc gases away from the conducting strap I1.

The manne;n of operation of my improved arc extinguisher will now be explained. In response to manual operation of the handle 4, or in response to tripping of an overload device asso- Vthe arc 53 toward the ciated with the interrupter I, the mechanism 5 is actuated to cause an upward separating motion of the movable contact arm 1 and movable contact t away from the stationary contact I3 to establish an arc 3l therebetween. Since the arc 3| is initially established Within an intense transverse magnetic field 30, as set up by the series blowout coils 25, 2E through the soft iron yoke 2l, the arc 3I will be forced ltoward the right, as viewed in Fig. 6, and into the spaced conducting plates 34 of the arc chute I9. The sever-al notches or slots 35 of the plates 34 align, as shown in Fig. 6, to form an arc passage 5I), within which the arc 3I is magnetically forced.

The arc 3I is bowed toward the right, as shown by the dotted line 5I of Fig. 6, and the lower end thereof quickly transfers to the arc plate horn 39. Also the arc 5I is attracted by the bight portion 52 (Fig. Y2) of the soft iron yoke 2I to cause it to transfer to the plates 34 and become usbdivided thereby, The arc then assumes the position 53 of Fig. 6, and it rapidly moves across the plates 34 to the right, until it strikes the gas-evolving front edge 38 of the fiber sheath or s arc plate support 33.

The arc 53, in coming into contact with the ber gas evolving sheath 33, will cause the evolution of gas therefrom, which will pass toward the left, as viewed in Fig. 6 and back through the arc stream, thereby deionzing the arc 53. Although the evolved gas tends to force left, as viewed in Fig. 6, and back out of the spaced plate structure. nevertheless the intense magnetic field 36 -acts in the opposite direction. As a result, the arc 53 is subjected tc two opposing forces, .one the force of the gas pressure from the evolved gas, and the other the magnetic force as exerted by the magnetic field 39. The net result is a rapid oscillating movement of the arc terminals upon the surfaces of the several conducting plates 34 to bring about rapid arc extinction. The rapid movement of the arc saves the plates from excessive heating in spots and prevents burning ofv holes through the plates.

It will be noted that I have used non-magnetic plates 34 which do not affect the magnetic field 35, and yet provide conducting surfaces for the arc sections 53a to move.` Preferably the plates 34 are formed of a suitable alloy, such as nickel and chromium alloyed together in a properl proportion, such as about nickel and about 20% chromium. Such a non-magnetic alloy does not disturb the magnetic flux field and yet is a good conductor and resists arc burning.

By having the are plate support 33 formed of a gas-evolving material, such as liber, there results considerable evolution of gas upon the contact of the arc 53 therewith. Since the gas must escape through the arc stream itself there is considerable turbulence set up, and the arc 53 is quickly extinguished.

My improved arc extinguisher is particularly suitable for the interruption of direct currents, but its use is not exclusively applicable thereto.

It will be observed that the arc chute I9 may easily be removed from the base 2 by remov.

ing the screw 45. It will also be observed Athat the rightward biasing force exerted upon the arc results from the cumulative effect of both the magnetic field 39 and also by the presence of the Vbight portion 52 of the yoke 2l. The bight portion 52 provides a low reluctance path for the magnetic field surrounding the arc 3I and distorts this field to cause rapid rightwa'rd moveaccusa I9, the arc is more effectively split up into smaller the throat of the lates sonably well isolated from each other. Also the arc is stretched a little more than usual by forcing it back into the arc chute I I.`

It will be observed that the arc chute I9 is relatively narrow and thus the arc is restricted instead of spread out. This increases the arc resistance which is very desirable in quenching arcs, especially direct current arcs.

It is to be noted that with the foregoing construction of the arc chute I9 most of the gases are formed at the back of the arc chute and very littleare formed at the side of the arc chute, because the arc is held toward the back of the tion, and that changes and modications ma art, without departing from the spiritand scope of the appended claims. .Y

I claim as my invention:

1. A Acircuit interrupter including a plurality of non-magnetic .spaced metallic plates, means.

for establishing an arc, magnetic means including a lil-shaped member of magnetic material outside of the plates and partially surrounding the same for moving the established arc laterally into the spacedmetallic plates to become subdivided thereby, the bight portion ofV the U-shaped .member plate, support member composed of gas-evolvingl i l I A connected electricallymin series with the contact means, the arc moving into engagement with the spaced conducting plates to become subdivided thereby, and the arc evolving gas from the gas-evolving support member to assist in deionizingthe arc. l i

3. A circuit interrupter including an arc chute comprising a substantially U-shaped support member composed of gas-evolving material and supporting a plurality of non-magnetic conducting plates in spaced relationship, contact means for'establishing an arc, a U-shaped magnetic yoke member partially surrounding the arc chute, a pair of electrically parallel energizing coils wound about the legs of the yoke member and y readily be made therein, by those skilled in thev connected electrically in series with the contact" means, the bight portion of the U-shaped magnetic yoke member toward the bight portion of the yoke member into engagement with the spaced conducting plates to become subdivided thereby, and the arc evolving gas from the gas-evolving support member to assist in deionizing the arc.

4. A circuit interrupter including a U-shaped yoke member composed of magnetic material, a plurality of spaced conducting non-magnetic plates disposed between the legs of the yoke member and adjacent the bight portion thereof, means for establishing an arc, and the bight por- -shaped yoke member being positoward the bight portion into engagement with the plates to become subdivided thereby.

5. A circuit interrupter including a U-shaped yoke member composed of magnetic material, an energizing winding wound about the yoke member, a plurality of spaced conducting non-magnetic plates disposed between the legs of the yoke member and adjacent the bight portion thereof, means for establishing an arc, and the bight portion of the U-shaped yoke member being posiends of the spaced plates opposite the arc-establishing means so that the arc moves towardthe bight portion into engagement with the plates to become subdivided thereby.

6. A circuit interrupter including a U-shaped yoke vmember composed of magnetic material, an energizing winding wound about the yoke member and electrically connected in series circuit, a plurality of spaced conducting non-magnetic plates disposed between the legs of the yoke member and adjacent the bight portion thereof, means for establishing an arc, and the bight portion of the U-shaped yoke member being positioned at the ends of the spaced plates opposite the arcestablishing means so that the arc moves toward the bight portion into engagement with the plates to become subdivided thereby.

' 7. A circuit interrupter including means for establishing an arc, an arc chute including a plurality of spaced non-magnetic conducting plates of a nickel-chromium alloy, and the arc moving into the plates to become subdivided thereby to effect the extinction thereof.

8. A circuit interrupter including means for establishing an arc, an arc chute including a plurality of spaced non-magnetic conducting plates, a pair of pole plates disposed on opposite sides of the arc chute, a magnetic frame for moving the arc magnetically interconnecting the pole plates, the bight portion of the magnetic frame being positioned at the ends of the spaced plates opposite the means for establishing the arc, an energizing winding about the magnetic frame to set up a magnetic field between the pole plates and transversely of the spaced non-magnetic plates to eiect movement of the arc thereon toward the bight portion of the frame, and the magnetic field being undisturbed by the nonmagnetic plates.

9. A circuit interrupter including a plurality of non-magnetic spaced metallic plates, means for establishing an arc, magnetic means for moving the established arc laterally into the spaced metallic plates to become subdivided thereby, the magnetic means including a U-shaped magnetic frame with the bight portion thereof being positioned at the ends of the spaced plates opposite being positioned at the ends the means? for establishing the arc,y the frame; at. least partially sur-rounding thev spaced non-f frame atleast partially surrounding the spaced. nonemagneticmetallic, plates, the-bight portion of; theU-shaped'magnetic frame being positioned` atY thel ends of. the, spaced platesI opposite the:

meansfor; establishingthe arc, oneorv more blowout. coils Wound about the magnetic frame to the arc space to effect' lateral motion ofthe arc, and the serially replates moving;

create magnetic flux in lated subdivided arcs. between the:

thereon to become extinguished.

1.1. A circuitinterrupter including an arc chute having a substantially U-shaped support laterally intothe spacedmember.- composed of gas-evolving material and I supporting a plurality ofnon-magnetic conducting= plates of anickelchromiumV alloy inspaced relationship, contactmeans for establishing an aro, a, U-shaped magnetic yoke member partially, surrounding the arc chute, a pair of electrically parallel energizing coilswound aboutthe legs of. the, yoke member of the U-shaped magnetic yoke member being positioned at the ends of the spaced plates oppositethe contact means for establishing the arc so.- thatthe arcmoves toward the bight portionof;v the yoke, member into engagement with the spaced conducting plates to become subdivided thereby, evolving support member to assist indeionizing the arc.

l2. A circuit interruptor including a pluralityj plates of a.

of non-magnetic spaced metallic nickelfchromium alloy,

an arc, member of magnetic material, outside of` the plates and partially surroundingv the same for means for establishing moving the established arc laterally into thespaced metallic plates to become. subdivided thereby, the bight portion of the U-shaped member of magnetic material ends of the spaced plates opposite the means for. establishing the arc,- and'aplate support member composed of gas-evolving materialto support the, plates in spaced relationshipthe arc engag plate support member toing` the gas-evolving evolve gas to-assistin the extinction of the arc.

13. A circuit interrupter member composed o1 gas-evolving material and supportinga plurality ofnon-magnetic conduct-- alloy in spacedv contact means for establishingan.- arc', `a Urshaped. magnetic yoke. member, par-- tially surrounding the arc chute,- l the. bight pore-- ing pla-,tes of a` nickel-chromium relationship,

tion ofthe.- U-shaped. magnetic yoke member being2 positioned attheends of i the rspaced plates. for establishingthe.-

opposite the Contact means arc', an= energizing coil= wound.- about the yoke member and connected electrically in series Withthe-contact means, the arc movingV into engagerment with the spaced conducting. plates to become subdivided thereby, and the arc.evolving gasy from the gas-evolving support member to assist in .deionizing the arc.

, 14.- A` circuit interrupter lincluding an arc chutey and connected electrically inseries Withthe contact meansthe bight portion.

andthe arc evolving gasgfrom the gas-- magnetic means including a U-shaped,

being positioned at they including an-arc chute" comprising a substantially U-shaped support.

'versely of' the spaced non-magnetic plates to comprisingfaf. substantiallyI U shaped` support,

memberv composedigof gas-evolving material and supporting aplurality of non-magnetic conduct.- ingplates-.of` a nickel-chromium alloy in spaced' i relationship, contact means for establishing an are,` al li-shaped magnetic yoke member partiallyv surrounding. theY arc chute;.a pair of electrically parailel energizingcoils Wound about the legs; and connected electrically. in: series withV thecontact meansthe.bight por-- tion offthe Ll.sh apedy magnetic yoke member be the spaced platesof-n the. yoke. member ing'. positionedy at the. ends. of opposite the contact means. for establishingv the arc so that the arc. moves toward thebight portion: ofi: the.y yoke, member into engagement. with. the spacedf` conducting plates to become. sub-- the arc evolving gas-fromthe gas-evolving.support-member to assistin de dividedu thereby, and

ionizingthe-arc.

15;,A.circuit interrupter including a U-shaped'. yoke.- member composedof magnetic material, a. conductingv non-magnetic plates orv anickel'fchromium. alloy disposed: be.- tweenithelegs. ofthe yoke member and adjacent the. bightr portion thereof, means. for establishf` ing an arc, and the bight portion of the Ushaped plurality ofy spaced! yokemember being positioned at the ends ofv the spacechplatesfoppositethe arc-establishing means. toward the. bightv portion.

so.- thatf the arc moves into' engagementY with?, theA plates` to: become subdivided thereby..

. 16;.A1circuit-'interruptor including a U-shaped. yoke member composed oimagnetic materiaLan.

energizing Winding wound' about. the yoke member., a plurality ofspaced conducting non-.mag-

netic platesof' a nickel-chromiumalloy disposed: the yokemember and adrjacentthebight portion thereof, meansfor es-` the bight portion o the: being positioned at the ends-of thezspacedplates oppositethe arc-estabtoward'the;

between the, legs. of

tabl'lshing. an arc, and U-shaped yoke-member lishing meansso-that the arc moves bight portion into engagement With the plates to become subdivided thereby.

17. A circuittinterrupter including a U-shaped yokesmember composedof magnetic material, an'

energizing Winding wound about the yoke membersand' electrically connected in series circuit,

a1 pluralityof spaced' conducting non-magnetic1 plates of a nickel-chromium alloy disposed' be tweentne legs oi' the yoke member and adjacent the-bight portionthereof, means for establishing an' arc, andthe bight portion ofthe U-shaped yoke member being-positioned at the ends of the spaced'lplates opposite the arc-establishing means sotliat-'the arc moves towardithe bight portion into engagement with the plates to become subdividedthereby.

-li8: A.'- circuit interrupter including means for establishing an arc, an arc chute including a plurality ofi spaced non-magnetic conducting plates-o a-nickel-kchromium alloy, a pair oi`=pole plates disposed on opposite sides-of the arc chute,

aA` magneticvframe for moving the arc magneti-- the pole plates, the bight portion of the magnetic framey being positioned' at the ends of they spaced plates opposite the.

cally interconnecting means for establishingV the arc, an energizing Winding about magnetic iield between the pole plates and transelectmovementlo. the arc thereon toward the bight portion of the frame, andthe magnetic. field beingY undisturbed by the non-magnetic. plates.-

the magnetic frame tok set upa 19. A circuit interrupter including a plurality of non-magnetic spaced metallic plates of a nickel-chromium alloy, means for establishing an arc, magnetic means for moving the established arc laterally into the spaced metallic plates to become subdivided thereby, the magnetic means including a U-shaped magnetic frame with the bight portion thereof being positioned at the ends of the spaced plates opposite the means for establishing the arc, the frame at least rounding the spaced non-magnetic metallic plates, and the serially related subdivided arcs between the plates moving thereon to become extinguished.

20. A circuit interrupter including a plurality of non-magnetic spaced metallic plates of a nickel-chromium alloy, means for establishing an arc, magnetic means for moving the established arc laterally into the spaced metallic plates to become subdivided thereby, the magnetic means including a U-shaped magnetic frame at least partially surrounding the spaced non-magnetic metallic plates, the bight portion of the U-shaped magnetic frame being positioned at the ends of the spaced plates opposite the means for come extinguished.

21. A circuit interrupter including means for establishing an arc and an arc chute for extinguishing the same, said arc-establishing means including a relatively stationary contact portion out coils, and the arc-establishing means drawing the arc in a direction substantially parallel to the bight portion of the U-shaped member of magnetic material so that the arc will be moved toward the bight portion.

22. A circuit interrupter including means for establishing an are and an arc chute for extinguishing the same, said arc-establishing means including a relatively stationary contact portion, a terminal projecting portion, a pair of blowout coils connected directly between the relatively stationary contact portion and the terminal projecting portion in electrical parallel, a U-shaped member of magnetic material extending through the pair of blowout coils so that a blowout coil ing means drawing the arc in a direction substantially parallel to the bight portion of the U- shaped member of magnetic material so that the arc will be moved toward the bight portion.

References Cited in the le of this patent UNITED STATES PATENTS Number Name Date 1,758,752 Kuhn May 13, 1930 2,047,302 Xardell July 14, 1936 2,133,158 Ver Planck et al. Oct. ll, 1938 2,236,580 Sandin et al Apr. 1, 1941 2,240,623 Lindstrom May 6, 1941 2,255,886 Hudson Sept. 16, 1941 2,268,338 Jackson et al Dec. 30, 1941 2,352,984 Walle July 4, 1944 2,363,606 Maseng Nov. 28, 1944 2,419,125 Dorfman et al. Apr. 15, 1947 FOREIGN PATENTS Number Country Date 219,723 Great Britain Aug. 5, 1924 

